Research finds no easy answers to use of drug screening for pain patients

Doctors who treat patients suffering from chronic pain face a quandary, according to research from the University of Houston and the University of Texas Medical Branch. Monitoring patients through urine drug screenings, part of the standard protocol to ensure patient safety, is associated with an increase in the odds that the patients won't return for future treatment.

The study, published in the February edition of Pain Physician, deals with an issue drawing increasing public attention. President Barack Obama earlier this month called for $1.1 billion in new federal money to combat problems linked to prescription drug abuse and heroin, including more treatment for people addicted to painkilling opioids such as OxyContin and hydrocodone.

That will require monitoring of patients treated with those drugs, but the study found monitoring may have some unintended consequences; almost one-fourth of chronic pain patients – 23.75 percent – who were given a urine drug screening test on their first visit failed to show up for their next appointment. That compares to just more than 10 percent of patients who were not screened. The trend applied even to patients whose drug screening indicated they had followed clinic rules.

"It is a balancing act," said Partha Krishnamurthy, a marketing professor and director of the Institute for Health Care Marketing at UH's Bauer College of Business. "On one hand, concerns about patient safety and public health necessitate the monitoring of patients on opioid medications. On the other hand, aggressive monitoring may interfere with the therapeutic alliance."

Krishnamurthy was lead author for the study, "Impact of Urine Drug Screening on No Shows and Dropouts among Chronic Pain Patients," along with co-authors Drs. Govindaraj Ranganathan, Courtney Williams and Gulshan Doulatram, all UTMB physicians who are board certified in pain management.

Drug screenings offer clues to patient behavior but also signal the patient that the doctor is watching.

"When you give a signal to the patient, it is likely to affect their decision making," Krishnamurthy said. He also has an appointment to UTMB, as an adjunct assistant professor in the Department of Anesthesiology and Pain Medicine.

The researchers found that 34.57 percent of patients who tested positive failed to show up for their next appointment; 21.74 percent of those whose screening tests were negative also failed to show up. About 10 percent of those who weren't tested skipped a follow-up appointment.

Those no-shows have implications for public health, as well as for individual patients, Krishnamurthy said, citing research showing prescribed opioid medications can be a precursor to heroin use or sold for recreational use. If these findings hold up in future controlled studies, he said, the big question will be "if monitoring patients makes them disengage from the clinic, where are they going?"

"While there is considerable research on the value of (urine drug screening) to the physician, there is little research on how it influences patient behavior," the researchers wrote. "The post-screening behavior of those receiving a (urine drug screening) was markedly different from those who did not."

Even patients who tested negative for illicit substances were more likely to skip a subsequent appointment than those who were not tested.

"This raises concerns that the (screenings) administered early in the doctor-patient relationship might have an inadvertent impact on injuring patient expectations of trust," according to the study.

The researchers did not recommend the screenings be stopped or delayed but emphasized the need to understand the impact of drug screening and how to mitigate any potential unintended effects.

The study drew upon the electronic medical records of 4,448 clinic encounters involving 723 patients between April 2009 and January 2012. Identifying information had been retracted.

That allowed the researchers to establish a correlation between urine drug screening tests and a patient's risk of skipping future appointments, but it did not clearly establish that the tests caused the patients to drop out. About 70 percent of patients were screened at their initial visit.

The findings held up through a variety of analytical models, but Krishnamurthy said the next step will be a controlled study, where patients are randomly assigned to be screened or not. Ultimately, he said, the goal is to balance use of opioid medications with patient safety and well-being.